Glucose/O₂ Biofuel Cell Operating at Physiological Conditions

Abstract

A glassy carbon electrode modified with bilirubin oxidase (BOD) cross-linked to an Os redox polymer functions as a bio-cathode for a 4-electron reduction of O₂ under neutral conditions. On the other hand, a glassy carbon electrode modified with pyrroloquinoline quinone-dependent soluble glucose dehydrogenase (sGDH) or glucose oxidase cross-linked to an Os redox polymer functions as a bio-anode for a 2-electron oxidation of glucose. A prototype of a one-compartment glucose/O₂ biofuel cell without a separator was constructed by using the BOD-modified cathode and the sGDH-modified anode. The maximum power density was 0.058 mW cm⁻². The loss in the power is discussed in terms of thermodynamics and kinetics.